Vitamins and sleep

Hello all,
I take a multivitamin/mineral each morning (they recommend 1-2x/day). Recently, I’ve started taking a second at night - I try to take it at dinner, but usually I don’t have them with me at that time so I just take it before I go to bed.
I’ve noticed that when I take it before sleeping, I don’t need to sleep as long - I’m waking up in the morning before my alarm sometimes, and it’s less than my usual amount. But I’m feeling just as awake and rested as if I’d slept as much as I needed.
I’m curious why this is. Anyone know? And is this bad for me? Or should I just be glad that I get an extra hour or two of awake time?

Sleep is extremely important, yet at times overrated. Depending on what your occupation is, it might be a blessing in disguise.